SOIL CARBON AND CLIMATE CHANGE NEWS
From Kansas State University's:
Consortium for Agricultural Soils Mitigation of Greenhouse Gases (CASMGS)
Charles W. Rice, K-State Department of Agronomy, National CASMGS Director
(785) 532-7217 firstname.lastname@example.org
Scott Staggenborg, K-State Department of Agronomy (785) 532-7214 email@example.com
Steve Watson, CASMGS Communications (785) 532-7105 firstname.lastname@example.org
June 11, 2009
Nitrous oxide and methane emissions
from continuous corn cropping in Ohio
A recent study by David A.N. Ussiri, Rattan Lal, and Marek K. Jarecki, at The Ohio State University, examined the effects of tillage practices on nitrous oxide (N2O) and methane (CH4) emissions in long-term continuous corn plots. This research is published in the July 2009 edition of Soil and Tillage Research.
N2O and CH4 have been linked to climate change. Conservation tillage practices such as no-tillage have potential to increase carbon sequestration in agricultural soils but patterns of N2O and CH4 emissions associated with no-till practices are variable.
The study was conducted on continuous corn experimental plots established in 1962 on a Crosby silt loam (fine, mixed, mesic Aeric Ochraqualf) in Ohio. The study consisted of no-till, chisel till, and moldboard plow till treatments. The N2O and CH4 fluxes were measured for one year at 2-week intervals during growing season and at 4-week intervals during the off season.
Long-term no-till significantly decreased soil bulk density and increased total nitrogen concentration of the 0–15 cm layer compared to moldboard plow and chisel till. Generally, no-till treatment contained higher soil moisture contents and lower soil temperatures in the surface soil than chisel till and moldboard plow till during summer, spring and autumn.
Average daily fluxes and annual N2O emissions were more in moldboard plow till and chisel till than no-till. On average, no-till was a sink for CH4, while moldboard plow till and chisel till were sources of CH4. Lower N2O emission and increased CH4 oxidation in the no-till practice are attributed to decrease in surface bulk density, suggesting increased gaseous exchange. The N2O flux was strongly correlated with precipitation, air and soil temperatures, but not with gravimetric moisture content.
Data from this study suggested that adoption of long-term no-till under continuous corn cropping system in the U.S. Corn Belt region may reduce Global Warming Potential associated with N2O and CH4 emissions by approximately 50% compared to moldboard plow till and chisel till management.
The complete article can be found at:
-- Steve Watson, CASMGS Communications